IMO as a DAC it is pretty good, but that headphone amp is questionable. Depending on what kind of headphones you're planning to drive with it, it might be insufficient to manage them well.
I don't think it is worth $500, but that is just my opinion.

The sample rates and formats are good DAC features to a certain degree. It certainly seems to offer a good variety. If implemented well, those features make a great DAC, but if the implementation is bad the DAC will be also. A clean power supply is everything on a DAC. You can get the same feature set from the SMSL Idea DAC/Amp which I'm skeptical of due to its size. There's no way there's enough cap in that thing to thoroughly clean up the power rails.
The amp side has some bass boost and what looks from the pictures like channel crossover control, but has fairly low output power.
For reference, CEntrance, which I know and love, has a couple offerings that are similar in their feature set but with a more powerful amp for around $350. I would rate those above the device you have linked, but that's mostly due to familiarity with CEntrance's quality of products and the fact that most of the features that are missing are ones that I'll never use.